ROS1 is a mutation that is similar to an ALK translocation, explains Feliciano. It has a similar configuration in the receptor. Many of the tyrosine kinase inhibitors (TKIs) that are effective for ALK are similarly effective for ROS1. Crizotinib (Xalkori) is approved for ROS1 mutations. Its efficacy reflects high response rates and long durations of response for patients with NSCLC. ROS1 occurs in about 1% of patients with NSCLC and tends to be mutually exclusive of ALK translocations, says Feliciano.

Other ALK inhibitors such as ceritinib (Zykadia) have been studied and show high response rates in ROS1. Lorlatinib is a later-generation TKI that has been shown to be effective in tumors that have become resistant to crizotinib, says Feliciano. However, there are common secondary mutations that can develop on most of these drugs, so physicians are now starting to develop regimens for resistance mutations.

ROS1 is a mutation that is similar to an ALK translocation, explains Feliciano. It has a similar configuration in the receptor. Many of the tyrosine kinase inhibitors (TKIs) that are effective for ALK are similarly effective for ROS1. Crizotinib (Xalkori) is approved for ROS1 mutations. Its efficacy reflects high response rates and long durations of response for patients with NSCLC. ROS1 occurs in about 1% of patients with NSCLC and tends to be mutually exclusive of ALK translocations, says Feliciano.

Other ALK inhibitors such as ceritinib (Zykadia) have been studied and show high response rates in ROS1. Lorlatinib is a later-generation TKI that has been shown to be effective in tumors that have become resistant to crizotinib, says Feliciano. However, there are common secondary mutations that can develop on most of these drugs, so physicians are now starting to develop regimens for resistance mutations.